200 gallon plywood build

[Backfromthedead]

My latest fish related project is my first plywood tank build. I designed it to serve as both a tank and a practical piece of furniture. Im around halfway done with the build and now getting into some uncharted territory for me, so i figured id make a build thread and see if anybody had suggestions or input.

Inside dimensions are 63"lx23"wx33"h, putting it somewhere in the vicinity of 200 gallons, which will be my largest tank yet. I have a 60"x30" sheet of tempered 1/2" glass which i plan to make a viewing window of 56"x26".

Like all of my projects, i reused as much scrap lumber and materials as i could, but couldnt really skimp out on the plywood as i needed two large sheets for the front and back.

I built two identical frames for the top and bottom of the tank, and connected them to two 40"x25" 6/4 wooden slabs which form the two rigid ends of the tank.

The slabs are honduran mahogany, which ive never worked with before but am pretty happy with the finish. They came from a single slab that was 12'x25". I have yet to finish the largest piece that will be the removable top of the tank.

I decided to cut in some of the extra plywood on the sides and installed the back piece last night.

I may add some more support to the bottom and vertical seams, but im not really sure if its necessary. I plan to coat all of the seams with fiberglass epoxy before applying the waterproofing.

Next step is cutting the viewing panel out of the front plywood, then i have to figure out what paint or finish to use on the front that will go well with the mahogany.

Thanks for reading. I'll keep updating as i move forward.

 

[Backfromthedead]

Well i was making good progress this morning with the front panel.


After i got it firmly secured with screws, i decided to do a fit test with my glass. Ran into a bit of problem.

Theres not enough room to get the panel into the tank!!!

Typical rookie mistake on a project like this. Didnt account for not having enough width to turn the glass once it was in the window. I guess its a good thing i tried the fit test before i put all the epoxy on though.

So i guess i have to do some deconstructjng and replanning now. Sort of a bummer of a setback though.

 

[Backfromthedead]

I was stymied for nearly a week due to the freezing temperatures and rain, but yesterday i did manage to get some work done. Hacksawed the crossbeams out so that problems solved and reinforced the vertical seams with some epoxy and corner cut pine. I was going to use fiberglass but really dont think its necessary and the weather has been delaying me enough as it is. I was able to get the first coat of flex seal on, think i may need another gallon before its done.

If anyone has a good idea for the stain or paint color for the front panel please offer it up because i am quite undecided.

 

[Backfromthedead]

Got the second coat of flex seal on last night. Hope to get the glass installed by tonight and fill testing by thursday. Definitely need some more flex seal for coating the crossbeams later on and other touch ups. Ive used a gallon+1 quart on roughly 40 sq ft.

Working on finishing the top of the tank as well. Such a pretty piece of wood.

After finish sanding-320 grit

And after the first coat of tung oil

Should be finished with it by thursday as well. Still thinking of a clever way to attach it to the tank.

 

[Backfromthedead]

Ive made slow progress over the last few weeks, but the tank is nearly ready now. When i first filled it, there was a small leak in my seal between the glass and tank that gave me quite a bit of trouble to fix. I ended up pouring fiberglass epoxy into the gap on the outside of the tank, and applying 2 more coats of flexseal to the inside.

And here it is painted and full of water.


I found a sweet piece of driftwood while at work the other day. Got some cleanup and a few cosmetic fixes to get done before i scape and install lighting, but all in all I'd say im a couple weeks out from completion.

 

[aae0130]

What is the reason for the slats underneath? Looks like you added them in the last picture.

 

[Backfromthedead]

What is the reason for the slats underneath? Looks like you added them in the last picture.

Oh i just have the tank sitting on those 2x4s temporarily. I already leak tested it outside, but still wanted to be able to look under it when i filled it the first time inside so i could track down a potential leak.

 

[aae0130]

Now that’s thinking “under” the box.

 

[Backfromthedead]

Doing some scaping. Gonna hang that other piece of wood to block the view of the large sponge filter and powerhead I'll be installing. Decided to hang all of it from the top to both maximize floor space and encourage activity in the top portions of the tank. Im loving how the solid wooden frame allows a lot of flexibility in scaping vs. A glass tank.

 

[filiportela]

Its looking great!